Catalytic converter

ABSTRACT

A catalytic converter includes at least one heating element that is configured to disrupt the direction of flow of exhaust gases which contain harmful toxic gases and pollutants and aid in removing and/or reducing said toxic gases and pollutants.

FIELD OF THE INVENTION

The present invention relates generally to catalytic converters for usewith flowing exhaust gases and more particularly to catalytic convertersthat have internal elements that are incorporated therein and/or addedthereto that disrupt the direction of flow of exhaust gases whichcontain harmful toxic gases and pollutants and aid in removing and/orreducing said toxic gases and pollutants.

BACKGROUND OF THE INVENTION

A catalytic converter is a vehicle emissions control device thatconverts toxic gases and pollutants in exhaust gas to less toxicpollutants, by catalyzing a redox reaction (oxidation or reduction).Catalytic converters are commonly used in conjunction with internalcombustion engines fueled by either gasoline or diesel.

Although catalytic converters are most commonly applied to exhaustsystems in automobiles, they are also used on electrical generators,forklifts, mining equipment, trucks, buses, locomotives, motorcycles,airplanes and wood stoves to control emissions.

A cordierite ceramic substrate is used in most catalytic converters. Forautomotive catalytic converters, the core of a catalytic converter isusually a ceramic monolith with a honeycomb structure. In applicationswhere particularly high heat resistance is required, metallic foilmonoliths made of Kanthal (FeCrAl) are commonly used. Both materials aredesigned to provide a large surface area.

Catalytic converters can include a washcoat, which is a carrier for thecatalytic materials that is used to disperse the materials over a largesurface area. Aluminum oxide, titanium dioxide, silicon dioxide, or amixture of silica and alumina can be used. The catalytic materials aresuspended in the washcoat prior to applying to the core. Washcoatmaterials are selected to form a rough, irregular surface, which greatlyincreases the surface area compared to the smooth surface of the baresubstrate. This in turn maximizes the catalytically active surfaceavailable to react with the engine exhaust.

Since 1981, “three-way” (oxidation-reduction) catalytic converters havebeen used in vehicle emission control systems in the United States andCanada. Many other countries have also adopted stringent vehicleemission regulations that in effect require three-way converters ongasoline-powered vehicles. The reduction and oxidation catalysts aretypically contained in a common housing. However, in some instances,they may be housed separately. A three-way catalytic converter has threesimultaneous tasks:

(1) Reduction of nitrogen oxides to nitrogen and oxygen: 2NOx→xO2+N2;

(2) Oxidation of carbon monoxide to carbon dioxide: 2CO+O2→2CO2; and

(3) Oxidation of unburnt hydrocarbons to carbon dioxide and water:CxH2x+2+[(3x+1)/2]O2 xCO2 +(x+1)H2).

Three-way catalysts are effective when the engine is operated within anarrow band of air-fuel ratios near stoichiometry such that the exhaustgas oscillates between rich (excess fuel) and lean (excess oxygen)conditions, which is between 14.6 and 14.8 parts air to 1 part fuel byweight for gasoline. The ratio for liquefied petroleum gas (LPG),natural gas and ethanol fuels is each slightly different, requiringmodified fuel system settings when using those fuels. However,conversion efficiency falls very rapidly when the engine is operatedoutside of that band of air-fuel ratios. Under lean engine operation,there is excess oxygen and the reduction of NOx is not favored. Underrich conditions, the excess fuel consumes all of the available oxygenprior to the catalyst, thus only stored oxygen is available for theoxidation function. Closed-loop control systems are necessary because ofthe conflicting requirements for effective NOx reduction and HCoxidation. The control system must prevent the NOx reduction catalystfrom becoming fully oxidized, yet replenish the oxygen storage materialto maintain its function as an oxidation catalyst.

U.S. Pat. No. 5,180,559, for example, is concerned with the inefficiencyof catalytic converters at low temperature, particularly duringlight-off time when an engine is first started and is directed to amethod for reducing the light off time that comprises exposing thematrix of the converter to an alternating magnetic field or toelectromagnetic radiation having such a frequency that the wash coat andthe particles of catalyst supported by the matrix are heated to thelight-off temperature without a corresponding increase in thetemperature of the entire matrix.

Static magnetic fields are not used once the materials have been heated.

SUMMARY OF THE INVENTION

The present invention is generally directed to a catalytic converterthat includes heating elements and a support lattice coated with acatalytic material. Disruptor plates can be located at inlet and outletports to add agitation to the flow of exhaust gases across the supportlattice and have an array of holes arranged across the direction of flowof the exhaust gases. The array of holes forms a pseudorandom pattern.The disruptor plates are oriented orthogonal to the longitudinal axis ofthe external shell.

In an embodiment, the catalytic converter can include a support latticethrough which a magnetic field is maintained to aid in the circulationof exhaust gases and other particulates in a catalytic converter. Therecan be an outer shell at least partially surrounding the external shellof a catalytic converter with a plurality of magnets located between theshells. The magnets can, for example, have a curved shape and/or can bearranged in sets. The magnets may lie in an array having alternatingpolarities. Magnets that face each other may also have opposing.Alternatively, magnets can have the same polarity and the polarity mightnot vary along the longitudinal direction of the converter. An array ofmagnets may be placed to abut the external shell from inside the shelland there may be a central core magnetic rod.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a cross-sectional view of a known catalytic converter;

FIG. 2 is a side view of a support lattice of the catalytic converter ofFIG. 1;

FIG. 3 is a cross-sectional view of a known catalytic converter withdisrupter plates;

FIGS. 4A-4C are side views of the disruptor plates of the catalyticconverter of FIG. 3;

FIG. 5 is a cross-sectional view of a catalytic converter withsupplemental heating elements and disruptor plates according to anexemplary embodiment of the present disclosure;

FIG. 6 is a cross-sectional view of a catalytic converter that includesexternal magnets;

FIG. 7 is an arrangement of the external magnets;

FIG. 8 is a cross-sectional view of a catalytic converter that includesinternal magnets according to an exemplary embodiment of the presentdisclosure;

FIG. 9A is a cross-sectional view of one of the internal magnets of thecatalytic converter of FIG. 8;

FIG. 9B is an exploded view of the internal magnets of the catalyticconverter of FIG. 8;

FIG. 10 is a partial cross-sectional view of an internal system of acatalytic converter that includes heaters and electrical systems relatedthereto according to an exemplary embodiment of the present disclosure;

FIG. 11 is a partial cross-sectional view of the catalytic convert ofFIG. 10 showing internal electrical heaters according to an exemplaryembodiment of the present disclosure;

FIG. 12 is a cross-sectional view of a catalytic convert of showingvarious possible locations of internal electrical heaters according toan exemplary embodiment of the present disclosure;

FIGS. 13A and 13B are a perspective and end view of a coil heather thatcan represent at least one heater included in a catalytic convertersystem of the present disclosure; and

FIG. 14 is an exemplary embodiment of another heater that can bearranged within catalytic converter.

DETAILED DESCRIPTION OF EMBODIMENTS OF THE INVENTION

With reference now to the drawings, and in particular to FIGS. 1-14,embodiments of catalytic converters embodying the principles andconcepts of the present invention will be described.

FIG. 1 illustrates a cross-sectional view of a catalytic converter 100that extends along a longitudinal axis 104 and comprises an externalshell 102, an inlet port 106 and an outlet port 108. Internal to theexternal shell 102 is an internal support lattice 110 that can bedivided into sections by spaces 112. Heating elements 114, which areconfigured to heat the internal temperature of the catalytic converter100, can be arranged within the spaces 112 of the lattice 100. Theheating elements 114 are configured to heat the internal temperature ofthe catalytic converter 100 which in turn aids in the removal of harmfulgases and particulate matter within the catalytic converter 100. Thesupport lattice 110 (see FIG. 2 for end view thereof) is coated with acatalytic material to maximize contact with toxic gases and particulatesand slow down the flow of these gases and particulates from the inletport 106 to the outlet port 108 to allow the heating elements to furtheraid in the removal of harmful gases and particulate matter within thecatalytic converter 100.

The coat must retain its surface area and prevent sintering of thecatalytic metal particles even at high temperatures (1000° C.). Thecatalyst itself, most often is a mix of precious metals. Platinum is themost active catalyst and is widely used, but is not suitable for allapplications because of unwanted additional reactions and high cost.Palladium and rhodium are two other precious metals used. Rhodium isused as a reduction catalyst, palladium is used as an oxidationcatalyst, and platinum is used both for reduction and oxidation. Cerium,iron, manganese and nickel are also used, although each has limitations.Nickel is not legal for use in the European Union because of itsreaction with carbon monoxide into toxic nickel tetracarbonyl. Coppercan be used everywhere except North America, where its use is illegalbecause of the formation of toxic dioxin.

FIG. 3 illustrates another exemplary embodiment of a catalytic converter200 with electrical heating elements 214 arranged in spaces 212.Electrical leads 216 extend from and supply energy to the heatingelements 214, which can be, for example, constructed of nichrome wire.It is noted that electrical leads 216 can also be used to supply energyto the heating elements 114 as depicted in FIG. 1. Here, disruptorplates 218 are placed near an inlet port 206 and an outlet port 208. Thedisruptor plates 218 are included to add agitation to the flow ofexhaust gases across support lattice 210. The support lattice 210,similar to the support lattice 110 shown in FIG. 1, is coated with acatalytic material to maximize contact with toxic gases and particulatesand further aid in slowing down the flow of these gases within thecatalytic converter and allow for the heating elements to at leastfurther reduce harmful gases and particulate matter.

FIGS. 4A-4C shows an end view of a disrupter plate 218 that includes ofan array of holes 220 that extend across the direction of flow of theexhaust gases. The array of holes are scattered about the plate 218 andare termed a pseudorandom pattern. As shown in FIG. 3, the disruptorplates 218 are oriented orthogonal to a longitudinal axis 204 of anexternal shell 202.

FIG. 5 depicts another exemplary embodiment of a catalytic converter 300of the present invention. The catalytic converter 300 includes heatingelements 314 arranged in openings 312 of the internal support lattice310 with electrical leads 316 extending therefrom to supply power to theheating elements 314 and secondary planar heating elements 315, 317 thatare arranged near an inlet port 306 and/or an outlet port 308, adjacentto disruptor plates 318. Additional electrical leads 319 supply energyto the secondary planar heating elements 315, 317. Although some of thevarious elements are described as planar or having particularorientations, it is not required that these geometrical restrictions beexact, and approximations thereto are within the description of thevarious embodiments. Disruption of normal, substantially lamellar flowof exhaust gases can lead to an enhancement of the efficiency of thecatalytic converter 300. As such, by including multiple heating elements314, 315, 317 and disrupter plates 318 the reduction of toxic gases andparticulate matter exiting a catalytic converter is greatly reduced.

The secondary heating elements 315, 317 can also be placed near afilter/support lattice 325 in addition to or in place of near the inletport 306 and/or outlet port 308. The catalytic converter 300 aids indestroying and removing harmful gases and particulate matter as theypass through the catalytic converter 300.

The secondary heating elements 315, 317 can be configured to heat theinternal temperature of the catalytic converter 300 to about 800° C. to1200° C. which aids in the removal of harmful gases and particulatematter within the catalytic converter 300. The support lattice/filter325 (see also FIG. 11) can be coated or sprayed with noble metals to aidin maintaining an internal temperature of about 800° C. to 1200° C. andin turn aid further in the removal of harmful gases and particulatematter.

FIG. 6 illustrates yet another exemplary embodiment of a catalyticconverter 400 that includes a support lattice 410 through which amagnetic field is maintained between an inlet port 406 and an outletport 408. Here, the catalytic converter 400 is enhanced with anencompassing shell 402 partially surrounding an external shell 403. Aplurality of magnets 40 are located between the shells 402, 403. Asshown in FIG. 7, the magnets 407 may have a curved shape to approximatethe outer geometry of the external shell 403 and may be provided in twosets 407′, 407″. The magnets 407 may lie in an array having alternatingpolarities as shown in FIGS. 7. Magnets 407 that face each other mayalso have opposing polarity although that is not required.Alternatively, the magnets 407 can have the same polarity and thepolarity might not vary along the longitudinal direction of theconverter 400. Having opposite polarity facing each other will result inthe stronger magnetic field.

It is noted that the electrical leads 316, 416 are attached to a controlunit (see FIG. 10) 421 that is capable of switching between the heatingunits 415, 417 (and 315, 317) and maintaining a desired temperature, asdesired at between about 10 and 30 amps.

FIG. 8 shows another exemplary embodiment of a catalytic converter 500of the present disclosure in which an array of magnets 507 are placed toabut an external shell 502 from inside the shell 502. Similar to otherembodiments, heating elements 514 are arranged in openings 512 ofsupport lattice 510 with electrical leads that power the heatingelements 514 extending from the heating elements 514.

FIG. 9A an end view of the magnets 507 and FIG. 8B depicts an explodedview of the magnets 507. It is noted that there may be a central coremagnetic rod 509 as part of the set of magnets 507. Such a core 509 isnot essential, but increases the possibility for different arrangementsof polarity of the magnets 507. For example, the outer magnets 507 thatface each other may have the same or different polarities, which mayvary along the longitudinal direction. In addition, the core magneticrod 509 may be one piece extending from the inlet port 506 to the outletport 508, with one polarity at each end or it may be made of segmentsthat are separated from each other in the longitudinal direction andhave polarities that vary in the longitudinal direction. Although themagnets 507 have been depicted as fixed magnets, they may also beelectromagnets maintained by current sources (not shown).

FIG. 10 depicts electronic connections of a catalytic converter.

As shown in FIG. 11, temperature sensors 325, 425 can be placed near theadditional heaters 315, 415, 317, 417 to aid in ensuring proper internaltemperature is maintained.

FIG. 12 depicts an exemplary embodiment of a catalytic converter of thepresent invention indicating that secondary heaters 315, 415, 317, 417can be placed at various locations within the catalytic converter andany number of secondary heaters can be used depending on the size of theunit.

FIGS. 13A and 13B depict an embodiment of one type of additional heater700 that that can be inserted into a catalytic converter from theoutside thereof and screwed in place. As such, the heater 600 is removalif needed.

FIG. 14 depicts another embodiment of an additional heater 800 that thatcan arranged in a catalytic converter.

In use, the catalytic converter 100, 200, 300, 400, 500 is placed sothat gases to be treated flow from the inlet port 106, 206, 306, 406,506 through disruptor plates 318 (in some embodiments), through asecondary heating element 114, 214, 314, 414, 515 and enter a volume inwhich they are subjected both to additional heating in some embodimentsfrom additional heaters 317, 318 and magnetic fields by magnets 407,507. The additional heaters and/or magnetic fields can interact with theindividual molecules and ions of the gases passing through catalyticconverters and increase the efficiency of catalytic conversion thattakes place before exiting a catalytic converter.

It is noted that in addition to heaters being included within acatalytic converter, they can be added to existing catalytic converters.

The foregoing description and accompanying drawings illustrateprinciples, exemplary embodiments, and modes of operation of the presentinvention. However, the present invention should not be construed asbeing limited to the particular embodiments disclosed herein. Variationsto the embodiments discussed above will be appreciated by those skilledin the art without departing from the scope of the invention.Accordingly, the above-described embodiments and accompanying drawingsshould be regarded as illustrative rather than restrictive.

What is claimed is:
 1. A catalytic converter, comprising: an external shell delimited at an inlet port and an outlet port; at least one heater arranged within the external shell that is configured to heat toxic gases and particulate matter that enters the catalytic and at least reduce said eliminate said gases and particulate matter prior to said gases and particulate matter exiting the catalytic converter.
 2. The catalytic converter of claim 1, further comprising a second shell spaced from the external shell and a plurality of magnets arranged between the external shell and the second shell.
 3. The catalytic converter of claim 1, wherein a plurality of heaters are arranged in the external shell with a first heater arranged near the inlet port and a second heater arranged near the outlet port.
 4. The catalytic converter of claim 1, further comprising a disrupter plate arranged adjacent the at least one heater.
 5. The catalytic converter of claim 1, further comprising a filter arranged within the external shell between the inlet port and the outlet port that is at least one of coated and sprayed with noble metals to aid in maintaining an internal temperature of the catalytic converter. 